1. Field of the Invention
This invention generally relates to systems for loading medical devices into deployment devices, and particularly to a system comprising an expandable medical device, a deployment device, and a loading device which loads the expandable medical device into the deployment device.
2. Background of the Invention
Stents and valves are known endoprostheses. Endoprostheses are generally radially-expandable, tubular structures that are configured to be delivered to a body vessel to support or repair the body vessel. During delivery of the endoprosthesis, the endoprosthesis remains in a radially compressed configuration in a deployment device. When the endoprosthesis is delivered to a treatment site within the body vessel, the endoprosthesis is then released from the deployment device, and expands to implant onto the body vessel wall.
Deployment devices are typically tubular device including an outer cross-sectional area that is sized to navigate through the body vessels or through the working channels of an endoscope or the like to the treatment site. Endoprosthesis, therefore, must be radially compressed to a cross sectional area in order to be loaded into the lumen of the deployment device via a compressing device, which commonly occurs at the manufacturing and/or assembly site. Some compressing devices may push the endoprosthesis through a funnel to radially compress the endoprosthesis to load into the delivery device, while other compressing devices may diminish the cross-sectional area of the endoprosthesis and then push the endoprosthesis into the catheter. These methods and systems have shortcomings for at least two reasons. First, pushing an uncompressed endoprosthesis into a funnel may fail due to insufficient column strength. Second, pushing a compressed endoprosthesis along the surface of the compressing device may fail due to wall friction. Regardless, the endoprosthesis may be compromised while pushing the endoprosthesis through the compressing device, compromising the drug coating, graft and/or valve material, and/or barbs.
Nevertheless, in the event that a vascular condition may be treated by virtue of the replacement endoprosthesis, the need arises to compress the aforementioned endoprosthesis for delivery. Some endoprosthesis, however, need to remain uncompressed up until the time of delivery. For example, an endoprosthesis with remodelable material may need to remain hydrated and uncompressed until delivery into the body. In the alternative, an endoprosthesis may be packaged separately from the deployment device. Such medical devices, nonetheless, must then be compressed into the deployment device at the bedside by the interventionalist. Thus, there remains a need for an apparatus and/or system to compress and load an endoprosthesis into a deployment device. There further remains a need to compress the endoprosthesis without compromising the drug coating, graft and/or valve material, and/or barbs, if present.